1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 /*
27 * This file is available under and governed by the GNU General Public
28 * License version 2 only, as published by the Free Software Foundation.
29 * However, the following notice accompanied the original version of this
30 * file, and Oracle licenses the original version of this file under the BSD
31 * license:
32 */
33 /*
34 Copyright 2009-2013 Attila Szegedi
35
36 Licensed under both the Apache License, Version 2.0 (the "Apache License")
37 and the BSD License (the "BSD License"), with licensee being free to
38 choose either of the two at their discretion.
39
40 You may not use this file except in compliance with either the Apache
41 License or the BSD License.
42
43 If you choose to use this file in compliance with the Apache License, the
44 following notice applies to you:
45
46 You may obtain a copy of the Apache License at
47
48 http://www.apache.org/licenses/LICENSE-2.0
49
50 Unless required by applicable law or agreed to in writing, software
51 distributed under the License is distributed on an "AS IS" BASIS,
52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
53 implied. See the License for the specific language governing
54 permissions and limitations under the License.
55
56 If you choose to use this file in compliance with the BSD License, the
57 following notice applies to you:
58
59 Redistribution and use in source and binary forms, with or without
60 modification, are permitted provided that the following conditions are
61 met:
62 * Redistributions of source code must retain the above copyright
63 notice, this list of conditions and the following disclaimer.
64 * Redistributions in binary form must reproduce the above copyright
65 notice, this list of conditions and the following disclaimer in the
66 documentation and/or other materials provided with the distribution.
67 * Neither the name of the copyright holder nor the names of
68 contributors may be used to endorse or promote products derived from
69 this software without specific prior written permission.
70
71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
82 */
83
84 package jdk.internal.dynalink.support;
85
86 import java.lang.invoke.MethodHandles;
87 import java.lang.invoke.MethodHandles.Lookup;
88 import java.lang.invoke.MethodType;
89 import java.lang.ref.Reference;
90 import java.lang.ref.WeakReference;
91 import java.util.Arrays;
92 import java.util.Collections;
93 import java.util.List;
94 import java.util.StringTokenizer;
95 import java.util.WeakHashMap;
96 import jdk.internal.dynalink.CallSiteDescriptor;
97
98 /**
99 * Usable as a default factory for call site descriptor implementations. It is weakly canonicalizing, meaning it will
100 * return the same immutable call site descriptor for identical inputs, i.e. repeated requests for a descriptor
101 * signifying public lookup for "dyn:getProp:color" of type "Object(Object)" will return the same object as long as
102 * a previously created, at least softly reachable one exists. It also uses several different implementations of the
103 * {@link CallSiteDescriptor} internally, and chooses the most space-efficient one based on the input.
104 * @author Attila Szegedi
105 */
106 public class CallSiteDescriptorFactory {
107 private static final WeakHashMap<CallSiteDescriptor, Reference<CallSiteDescriptor>> publicDescs =
108 new WeakHashMap<>();
109
110
111 private CallSiteDescriptorFactory() {
112 }
113
114 /**
115 * Creates a new call site descriptor instance. The actual underlying class of the instance is dependent on the
116 * passed arguments to be space efficient; i.e. if you only use the public lookup, you'll get back an
117 * implementation that doesn't waste space on storing the lookup object.
118 * @param lookup the lookup that determines access rights at the call site. If your language runtime doesn't have
119 * equivalents of Java access concepts, just use {@link MethodHandles#publicLookup()}. Must not be null.
120 * @param name the name of the method at the call site. Must not be null.
121 * @param methodType the type of the method at the call site. Must not be null.
122 * @return a call site descriptor representing the input. Note that although the method name is "create", it will
123 * in fact return a weakly-referenced canonical instance.
124 */
125 public static CallSiteDescriptor create(final Lookup lookup, final String name, final MethodType methodType) {
126 name.getClass(); // NPE check
127 methodType.getClass(); // NPE check
128 lookup.getClass(); // NPE check
129 final String[] tokenizedName = tokenizeName(name);
130 if(isPublicLookup(lookup)) {
131 return getCanonicalPublicDescriptor(createPublicCallSiteDescriptor(tokenizedName, methodType));
132 }
133 return new LookupCallSiteDescriptor(tokenizedName, methodType, lookup);
134 }
135
136 static CallSiteDescriptor getCanonicalPublicDescriptor(final CallSiteDescriptor desc) {
137 synchronized(publicDescs) {
138 final Reference<CallSiteDescriptor> ref = publicDescs.get(desc);
139 if(ref != null) {
140 final CallSiteDescriptor canonical = ref.get();
141 if(canonical != null) {
142 return canonical;
143 }
144 }
145 publicDescs.put(desc, createReference(desc));
146 }
147 return desc;
148 }
149
150 /**
151 * Override this to use a different kind of references for the cache
152 * @param desc desc
153 * @return reference
154 */
155 protected static Reference<CallSiteDescriptor> createReference(final CallSiteDescriptor desc) {
156 return new WeakReference<>(desc);
157 }
158
159 private static CallSiteDescriptor createPublicCallSiteDescriptor(final String[] tokenizedName, final MethodType methodType) {
160 final int l = tokenizedName.length;
161 if(l > 0 && tokenizedName[0] == "dyn") {
162 if(l == 2) {
163 return new UnnamedDynCallSiteDescriptor(tokenizedName[1], methodType);
164 } if (l == 3) {
165 return new NamedDynCallSiteDescriptor(tokenizedName[1], tokenizedName[2], methodType);
166 }
167 }
168 return new DefaultCallSiteDescriptor(tokenizedName, methodType);
169 }
170
171 private static boolean isPublicLookup(final Lookup lookup) {
172 return lookup == MethodHandles.publicLookup();
173 }
174
175 /**
176 * Tokenizes the composite name along colons, as well as {@link NameCodec#decode(String) demangles} and interns
177 * the tokens. The first two tokens are not demangled as they are supposed to be the naming scheme and the name of
178 * the operation which can be expected to consist of just alphabetical characters.
179 * @param name the composite name consisting of colon-separated, possibly mangled tokens.
180 * @return an array of tokens
181 */
182 public static String[] tokenizeName(final String name) {
183 final StringTokenizer tok = new StringTokenizer(name, CallSiteDescriptor.TOKEN_DELIMITER);
184 final String[] tokens = new String[tok.countTokens()];
185 for(int i = 0; i < tokens.length; ++i) {
186 String token = tok.nextToken();
187 if(i > 1) {
188 token = NameCodec.decode(token);
189 }
190 tokens[i] = token.intern();
191 }
192 return tokens;
193 }
194
195 /**
196 * Tokenizes a composite operation name along pipe characters. I.e. if you have a "dyn:getElem|getProp|getMethod"
197 * operation, returns a list of ["getElem", "getProp", "getMethod"]. The tokens are not interned.
198 * @param desc the call site descriptor with the operation
199 * @return a list of tokens
200 */
201 public static List<String> tokenizeOperators(final CallSiteDescriptor desc) {
202 final String ops = desc.getNameToken(CallSiteDescriptor.OPERATOR);
203 final StringTokenizer tok = new StringTokenizer(ops, CallSiteDescriptor.OPERATOR_DELIMITER);
204 final int count = tok.countTokens();
205 if(count == 1) {
206 return Collections.singletonList(ops);
207 }
208 final String[] tokens = new String[count];
209 for(int i = 0; i < count; ++i) {
210 tokens[i] = tok.nextToken();
211 }
212 return Arrays.asList(tokens);
213 }
214
215 /**
216 * Returns a new call site descriptor that is identical to the passed one, except that it has some parameter types
217 * removed from its method type.
218 * @param desc the original call site descriptor
219 * @param start index of the first parameter to remove
220 * @param end index of the first parameter to not remove
221 * @return a new call site descriptor with modified method type
222 */
223 public static CallSiteDescriptor dropParameterTypes(final CallSiteDescriptor desc, final int start, final int end) {
224 return desc.changeMethodType(desc.getMethodType().dropParameterTypes(start, end));
225 }
226
227 /**
228 * Returns a new call site descriptor that is identical to the passed one, except that it has a single parameter
229 * type changed in its method type.
230 * @param desc the original call site descriptor
231 * @param num index of the parameter to change
232 * @param nptype the new parameter type
233 * @return a new call site descriptor with modified method type
234 */
235 public static CallSiteDescriptor changeParameterType(final CallSiteDescriptor desc, final int num, final Class<?> nptype) {
236 return desc.changeMethodType(desc.getMethodType().changeParameterType(num, nptype));
237 }
238
239 /**
240 * Returns a new call site descriptor that is identical to the passed one, except that it has the return type
241 * changed in its method type.
242 * @param desc the original call site descriptor
243 * @param nrtype the new return type
244 * @return a new call site descriptor with modified method type
245 */
246 public static CallSiteDescriptor changeReturnType(final CallSiteDescriptor desc, final Class<?> nrtype) {
247 return desc.changeMethodType(desc.getMethodType().changeReturnType(nrtype));
248 }
249
250 /**
251 * Returns a new call site descriptor that is identical to the passed one, except that it has additional parameter
252 * types inserted into its method type.
253 * @param desc the original call site descriptor
254 * @param num index at which the new parameters are inserted
255 * @param ptypesToInsert the new types to insert
256 * @return a new call site descriptor with modified method type
257 */
258 public static CallSiteDescriptor insertParameterTypes(final CallSiteDescriptor desc, final int num, final Class<?>... ptypesToInsert) {
259 return desc.changeMethodType(desc.getMethodType().insertParameterTypes(num, ptypesToInsert));
260 }
261
262 /**
263 * Returns a new call site descriptor that is identical to the passed one, except that it has additional parameter
264 * types inserted into its method type.
265 * @param desc the original call site descriptor
266 * @param num index at which the new parameters are inserted
267 * @param ptypesToInsert the new types to insert
268 * @return a new call site descriptor with modified method type
269 */
270 public static CallSiteDescriptor insertParameterTypes(final CallSiteDescriptor desc, final int num, final List<Class<?>> ptypesToInsert) {
271 return desc.changeMethodType(desc.getMethodType().insertParameterTypes(num, ptypesToInsert));
272 }
273 }